A voice user interface (VUI) allows a human user to interact with an intelligent, electronic device (e.g., a computer) by merely “talking” to the device. The electronic device is thus able to receive, and respond to, directions, commands, instructions, or requests issued verbally by the human user. As such, a VUI facilitates the use of the device.
A typical VUI is implemented using various techniques which enable an electronic device to “understand” particular words or phrases spoken by the human user, and to output or “speak” the same or different words/phrases for prompting, or responding to, the user. The words or phrases understood and/or spoken by a device constitute its “vocabulary.” In general, the number of words/phrases within a device's vocabulary is directly related to the computing power which supports its VUI. Thus, a device with more computing power can understand more words or phrases than a device with less computing power.
Many modern electronic devices, such as personal digital assistants (PDAs), radios, stereo systems, television sets, remote controls, household security systems, cable and satellite receivers, video game stations, automotive dashboard electronics, household appliances, and the like, have some computing power, but typically not enough to support a sophisticated VUI with a large vocabulary—i.e., a VUI capable of understanding and/or speaking many words and phrases. Accordingly, it is generally pointless to attempt to implement a VUI on such devices as the speech recognition and speech output capabilities would be far too limited for practical use.